Genetics calculation grrr!

[milkbat]

Hey guys, If anyone could help me out I would be grateful! I have no idea what the genotypes are for these. I thought maybe Z^bZ for the male, and Z^BW For the female... But that seems too easy.

Any help appreciated. Thank you!

 

In chickens, males have two Z sex chromosomes (ZZ) and females have one Z and one W sex chromosome (ZW). The mechanism for inheritance of the sex chromosomes is exactly the same as for X and Y sex chromosomes in other species. In chickens the character of 'barred' or striped feathers is Z-chromosome linked. The barred feather allele ZB is dominant to the non-barred feather allele Zb. Write down the genotype that would result in a non-barred male and a barred female and explain why these are the only genotypes that could result in these phenotypes.

Edited April 26, 2012 by milkbat

[The Flaming Goldfish]

Hey guys, If anyone could help me out I would be grateful! I have no idea what the genotypes are for these. I thought maybe Z^bZ for the male, and Z^BW For the female... But that seems too easy.

Any help appreciated. Thank you!

 

In chickens, males have two Z sex chromosomes (ZZ) and females have one Z and one W sex chromosome (ZW). The mechanism for inheritance of the sex chromosomes is exactly the same as for X and Y sex chromosomes in other species. In chickens the character of 'barred' or striped feathers is Z-chromosome linked. The barred feather allele ZB is dominant to the non-barred feather allele Zb. Write down the genotype that would result in a non-barred male and a barred female and explain why these are the only genotypes that could result in these phenotypes.

 

As far as I see, your genotypes are partially correct. The only thing is that the second Z chromosome for the male chicken would also have to have a genotype for this allele. So the phenotype

 

 

The red Z^bZ^b is your non-barred male, and the Z^BW is your barred female. The reason this is the only genotype that works is because all the others would produce the wrong results.

Edited April 27, 2012 by The Flaming Goldfish